Smoke ammunition containing liquid smoke producer and an absorption active powder



Aug. 5, 1969 R. v. AKHAGEN 3,45 9

SMOKE AMMUNITION CONTAINING LIQUID SMOKE PRODUCER AND AN ABSORPTIONACTIVE POWDER Filed July 5, 1967 190 na ernerflkfia em United StatesPatent Oflice 3,459,129 SMOKE AMMUNITION CONTAINING LIQUID SMOKEPRODUCER AND AN ABSORPTION ACTIVE POWDER Rune V. Akhagen, Eskilstuna,Sweden, assignor to Forsvarets Fabriksverk, Stockholm, Sweden, acorporation of Sweden Filed July 5, 1967, Ser. No. 651,114 Claimspriority, application Sweden, July 13, 1966, 9,572/ 66 Int. Cl. F42b13/44 U.S. Cl. 102-90 1 Claim ABSTRACT OF THE DISCLOSURE Smokeammunition containing a smoke composition, the main part of which is aliquid smoke producer, preferably titanium tetrachloride, -15 of weightof the composition consists of a well dried powder of synthetic calciumsilicate, the pulverization degree of which corresponds to an adsorbingarea of at least 50 m. g. The smoke composition brings about a spreadingof the smoke over a larger area and facilitates the use of liquid smokeproducers in spin stabilized shells.

The smoke ammunition which is used in the majority of the militaryforces concerns generation of momentary or continuous smoke. It usuallytakes more than one minute for generating the continuous smoke. Duringthis time a rather constant quantity of smoke is emitted per unit oftime from the smoke-producing object, which is spread by the wind onlyin the direction of the wind. This kind of smoke is in the first placesuitable for undertakings requiring a comparatively long duration and ascreened area of great width. The momentary smoke is characterized inthis that the quantity of smoke is generated practically momentary,i.e., within a space of about one second. The smoke developssubstantially into a spherical cloud of smoke, which, depending on itsinherent heat, prevailing air temperature, air humidity and windvelocity etc. is spreading, rising and laterally moving. This kind ofsmoke is in the first place suitable for smoke-undertakings requiring arapid screening-effect within a very limited area.

The momentary smoke-producers may be solids or liquids. Of thefirst-mentioned ones yellow phosphorous is considered to be mostefiective but it has disadvantages because of its strongly exothermalreactions. This involves not only a considerable danger of fire but alsoa rapid rising of the generated cloud of smoke uncovering the target(so-called pillar-effect).

As liquid smoke-producers for a momentary smoke covering smoke-acid(HCISO +SO titanium tetrachloride and stannic chloride are used. Anadvantage of these smoke producers is, that they generate a very densesmoke, but it is a disadvantage, that the smoke cannot be fully utilizedby the burst of the casing which burst is necessary for their spreadingsince they will be atomized to such a degree that the fluid particleswill rapidly react with the water vapour of the air also when the airhumidity is low. In this way the produced cloud will be of a smallextent, and the fact that its density is higher than required cannot beutilized.

The present invention relates to ammunition having a liquid smokeproducer, especially titanium tetrachloride for producing a momentarysmoke covering and has for its purpose to bring about an improvedspreading of the smoke covering while maintaining a required density ofthe same.

According to the principal characteristic features of 3,459,129 PatentedAug. 5, 1969 the invention the smoke producer is mixed with a well driedpowder of a synthetic calcium silicate or another material havingcorresponding adsorption qualities and the powder makes between 5 and 15percentage by weight of this mixture, whereby the pulverization degreecorresponds to an adsorption area of at least 50 mF/g.

The explanation of the spreading eflect otbained by intermixing anadsorption active powder with the smoke producer may be, that thereaction of the latter with the moisture of the air will be delayed, sothat the particles of the smoke producer adsorbed on the powder grainswill have time to spread over a larger area before they react with theair moisture.

A powder which is particularly suitable for this purpose consists of asynthetic calcium silicate, which by high grade pulverization has beengiven an adsorption area of more than 50 mfl/g. A powder of this type,which is industrially produced in qualities having an adsorption area ofup to m. g. is on sale under the trade name of Micro Cel. The fact isthat within certain bounds the more fine-grained the powder is thesmaller quantity of it needs be intermixed for the delay elfect to beobtained, which implies that a larger quantity of smoke producer can beretained. Made experiments have proved that a smoke composition,consisting of 515% of powder and for the remainder of a liquid smokeproducer, will give a utilizable improvement of the smoke coveringeflect of the smoke producer.

Of course even other powders than the above mentioned synthetic calciumsilicate can be used, if they have adsorption qualities of the sameorder of magnitude.

Only a well dried powder can be used, since the smoke producer even whensmall quantities of water are present will be decomposed and give offcorroding components, which, when titanium tetrachloride or stannicchloride is used as smoke producer, consist of hydrochloric acid. Thelatter attacks among other things aluminium, which is a usual ingredientof smoke shells or other objects, being charged with a smoke producer.

The suggested intermixing of an extremely fine-grained adsorption activematerial with a liquid smoke producer is also a contribution to thesolution of another problem, namely to be able to use a liquid smokesubstance in spin stabilized shells without withdrawing it from itsparticipation in the rotation of the shell, the consequence of whichwould be lack of balance, impairing the steering of the shell. By theintermixed powder the viscosity of the smoke composition will be so highthat the smoke composition will substantially participate in the rotarymotion or can by simple means be made to do so. Such a means consists oflists or corresponding members, which serving as carriers are arrangedon the inside of and coaxially with the casing of the smoke composition.For the above mentioned reason it is important that the percentage ofpowder in the smoke composition is high in spin stabilized shells. Fornatural reasons, however, the quantity of smoke producer must not be toosmall.

A powder of calcium silicate with an adsorption area of 50150 mP/g. hasproved to give favorable results regarding the balance of the projectileas well as the density and the extent of the smoke covering, if itsproportion of the smoke composition is 10-15 percentage by weight.

The present invention is illustrated in the acompanying drawing whichshows a longitudinal section of a smoke shell. The shell comprises ashell body 1 having a container 2 housing a detonator 3. The spacebetween the shell body 1 and the container 2 is filled with a smokecomposition 4 consisting of titanium tetrachloride and pulverizedcalcium silicate as described above.

I claim:

1. Smoke ammunition for producing a momentary smoke generation with gooddensity as Well as a broad spreading comprising, a hollow bodycontaining a liquid smoke producer and a detonator for bursting thehollow body, characterized in that the smoke producer is mixed with adry powder of synthetic calcium silicate and that said dry powderconstitutes 5-15 percentage by weight of the mixture, whereby thepulverization degree corresponds to an adsorption area of at least 50 m.g. of said dry powder.

References Cited UNITED STATES PATENTS 2,115,608 4/ 1938 Brandt 102-662,175,790 10/1939 Booker et al 10266 3,103,888 9/ 1963 Rosenthal 102-664 FOREIGN PATENTS 1,199,660 8/1965 Germany.

OTHER REFERENCES The Condensed Chemical Dictionary by Rose, fifthedition, Reinhold Pub. Co. (1956), pp. 503 and 739.

Smiths College Chemistry by Ehret, sixth edition, D. Appleton, CenturyComp. Inc., (1946), p. 451.

0 BENJAMIN A. BO-RCHELT, Primary Examiner J. FOX, Assistant ExaminerU.S. Cl. X.R.

